Automobile brake



P. H.A MCNELLES AUTOMOBILE: BRAKE April 3o, 1929.

vFiled March 14,v 1927 4 sheets-sheet 1 A TTORNE Y.

April 3.0, 1929 P. H. McNELLEs 1,711,321

l AUTOMOBILE BRAKE Filed March 14, 192.7 4 sheets-sheet 2 INVENTOR.

A TTORNEY.'

April 30, 1929. P. H. MCNLLES AUTOMOBILE BRAKE Filed March 14, 1927 v 4sheets-sheet 5 ATTRNEY.

April 30, 1929. P. H.. McNLLES 1,711,321

AUTOMOBILE BRAKE Filed March 14, 1927 4 SheeftsSheet 4\\\\\\\\\\\\\\\\\\\\\\\\\\vAk IA lill. llnlllmu A TT ORNE Y.

Patented Apr. 30. 1929...

UNITED gSTATES l 1,711,321 PATENT OFFICE.

PHILIP MCNELLES, OF DETROIT, MICHIGAN AUTOMOBILE BRAKE.

Application mea March 14, 1927. semi No. 175,108..

tThis invention relates to automobile brakes andthe object of t-heinvention is to provide aslouble brake operating simultaneously on theinternal and external faces of they brake drum..

Another object of the invention is to provide a means for operating thebrake cono I u 5 sistingv 1n a means for moving two brake shoes A'urtherobject of the invention is to provide a brake operating on the internaland external faces of a brake drum simultaneously upon application ofthebrake.

Ag further object of the invention is to pro vide a means for moving theouter and inner sets of brake shoes in opposite directions by movementof a single lever.

These objects and the several novel features of the invention arehereinafter more fully described and claimed and the preferred form ofconstruction by which'these objects are at\ Fig. 3.

i Fig. 1.

tained is shown in the accompanying drawings in which-"- Y Fig. 1 isa-verticalsection through an automobile wheel and brake embodying myinvention.-

Fig. 2 is a Fig. 1.

vF ig. 3 1s a section' taken on line 3-I-3 of section taken on line 2*2of 'Fig 4 Fig; 2. f

Fig. 5 is a partial section similar to Fig. 2 showing the brake shoes inbraking position. Fig. 6 is -a section taken on line -6-6 ot isasection'taken on line'4-4of Fig. 7 is a section taken on line 7 7 ofFig. 3. k

Fig. 8 is a section taken on li e 8-8 of Fig. 2.

`As shown in Fig. 1 the brake is adapted to be actuated by a rod 1 whichmay be turned by means of 'a lever-2 which is ixedly secured to therod 1. The rod 1 extends through a stationary plate 3 which is securedto the axle housing 4. Two sprockets 5 and 6 are secured to the rod 1 onopposite sides of the plate 3 and provide means for actuating thevbrake. The wheel maybe either a wood or wire spoke wheel or a disc wheelas shown in which the brake drum 7 is secured to rop tate with thewheel. The interior of the drum 'is shown in Fig. 2 and a brake shoe 8is provided having a brake lining 9 and having an lextending end 10. Aseries of three pins `11 are secured in the plate 3 and extend throughslots 12 in the brake shoe 8 so that the brake shoe may be movedupwardly on the pins 11 to apply the brake lining 9 to the innerace ofthe drum. The other brake shoe 13 is provided with a brake lining 14 andis slidable in 4thesame manner on the pins 15 which are secured in thestationary plate 3. By a downward movement of the brake shoe 13 thebrake lining 14 is also appliedI to the inner-l face of the brake drum7. A rack 16 is secured to the extending end 17 of the brake shoe 13 anda rack 18 is secured to the extension 10 4of the brake shoe 8. Theseracks both mesh with the sprocket gear 6 so that upon turning thesprocket gear 6 in a counter clock- Wise direction theI brake shoe 13 ismoved downwardly while the brake shoe 8 is moved upwardly. This movementof the sprocket 6 is accomplished by turning the yrod 1 by means of thelever 2 Which-moves the brake shoes 8 and 13 apart to apply the brake.In order -to return the brake shoes to the inoperative position'shown inFig. 2 a pair of springs 19 are provided connecting the ends of thebrake shoes and tending to draw the brake shoes I toward the center ofthe wheel; The internal brakes are shown in position for applying thebrake in Fig. 5. i

The outer brakeshoes are shown more particularly in Fig. 3 in which thebrake shoe 2O is 'arcuate in form and is provided with an extending end21 and the brake shoe 22, which 'is similar to the brake shoe 20, isprovided with an extending arm 23. A rack 24 is secured' to this .arm 23while a rack 25 is secured to the arm 21 of the brake shoe 20. Both' ofthese .l

racks 24 and 25 mesh withthe sprocket 5 on the rod or shaft 1. By thisarrangement upon rotation of the sprocket 5 in a clockwise direction therack 24 isgmoved upwardly thus drawing the outer brake shoe 22 intocontact with the outer face of the brake drum and at the ;sa1ne time therack 25 is'moved. downwardly to draw the outer brake shoe 20 into 2l ofa brake shoe 20. The brake shoe 224 is also provided with two guides 32for the arm 21. The upper brake shoe 2O is pro vided with a pin 33extending through a slot 34m the arin 23 of the brake shoe 22 and thebrake shoe 20 is provided with guides 35 for the arm 23.' The brake shoe20 is also providedl with lugs 36 on the inner face riding in the slots37 in the stationary plate 3 and the brake shoe 22 is provided with lugs38 on the inner face thereof riding in the slots 39 iny the plate 3 asit will be more readily understood from Figs. 3 and 7. Two members 40are secured to opposite sides of the plate 3 and are under cut as shownin dotted lines to provide guides for the ends of the brake shoes 20 and22. `With this arrangementlboth brake shoes 20 and 22 are guided intheirninovement to apply `the brake.

The llever 2 shown in Fig. 1 may be operated by a hydraulic means ormechanical means as desired. When the sprockets 5 and G aie turned bymeans of the lever 2 and rod 1 the inner brake shoes are moved outwardlyand the outer brake shoes are movedV inwardly to grip the brake drum.Upon release of the brake the springs 19 draw the inner brake shoes awayfrom the brake drum toward thecenter of the wheel thus turning thesprocket 6 which is secured to the rod 1 and thus the sprocket 5 isturned to nieve the outer brake shoes apart away fromthe brake drum.

By theuse of the two slices which are moved diametrically of the brakedrum the pressure applied in actuating the brake is uniform throughoutthe surfaces of the brake shoes and therefore the brake linings willwear uuiformly and will not tend to wear throughat any one point whichis a fault of the usual brake which surrounds the drum in which the twoends of the brake band are drawn together to apply the brake.

From the foregoing description it becomes evident that the device isvery simple and efficient in operation, will provide a brake of maximumpower which will not easily get out of order and provides a device whichaccomplishes the objects described.

Having thus fully described my invention, its utility and mode ofoperation, what I claim and desi re to secure by Letters Patent of theUnited States is- 1. In an automobile brake, a brake drum,

a pair of arcuate outer brake shoes positioned in spaced relation withthe outer face of thel brake drum, a pair ,of arcuate inner brake shoespositioned in spaced relation witli'the inner face of the bra-ke drum, atoothed rack on each brake shoe, a sprocket meshing with the racks ofthe outer brake shoes and adapted upon rotation to move the outer brakeshoes in opposite directions, a second sprocket.

plate adapted to be secured to an axle housing, a brake drum adapted tobe secured to an automobile wheel, a pair of outer brake shoes slidablmymounted on the stationary plate and extending over the outer face ofthelbrake drum, a pair of inner brake shoes slidably mountedon thestationary plate within thebrake drum, a toothed rack secured to eachbrake shoe, a sprocket meshing with the racks on the inner` brake shoes,a second sprocket meshing with the iacks on the outei' b rake shoes anda shaftwrotatable in the stationary plate to which the sprockets aresecured.`

3. In an automobile brake, a'brake drum, a

pair of outer brake shoes positioned in spaced relation with the outerface of the brake drum, a pair of inner brake shoes positioned in spacedrelation with the inner face of the brake drum, a toothed rack on eachbrake shoe, a sprocket meshing with the racks of the outer brake shoes,a second sprocket meshing with the racks of the inner brake slices and arotatable shaft to which both sprockets are secured.

4. In an automobile brake, a stationary plat-e adapted to be secured toan axle housing, a brake drum secured to the automobile wheel adjacentthe plate, a pairI of outer brake shoes slidably mounted indiametrically opposed relation on the extei'ior face of the plate andextending over the outer face of the drum, a pair of inner bra'kc shoesslidably mounted in diametrically opposed relation on the inner face ofthe plate within the brake drum, a toothed rack secured to each brakeshoe, the racks of the inner shoes on the inner side of the plate beingin opposed relation oi'i one side of the axle housing and the racks ofthe outer slices being secured in alignment therewith on the saine sideof the axle and on the opposite side of the plate, a shaft supported inthe plate between opposed pairs of racks, and gear means attached to theshaft and meshing with each or' the racks providing an arrangementwhereby rotation of the shaft inv either direction causes correspondingmovement of the slices.

In testimony whereof I sign this specification.

PHILIP H. MCNELLES.

